Various designs of such ball-and-socket joints have been known. They are used, e.g., as support joints or as guiding joints in the area of the wheel suspension. These types of joints have a housing open on one side, into which a one-part or multipart bearing shell is inserted. The joint ball of a ball pivot, which exits from the housing side that is open on one side and which is provided with a connection contour on the side located opposite the joint ball, is accommodated within the bearing shell movably in all directions.
For example, threads or fits, which may in turn be combined with grooves milled in the ball pivot, are used as the connection contour in the known manner. A bolt inserted into the wheel carrier engages this groove, and the bolt thus acts as a captivating means.
A sealing element in the form of a bellows, which surrounds the ball pivot, on the one hand, and is sealingly fixed at the housing of the ball-and-socket joint, on the other hand, is usually used as a sealing means for the ball-and-socket joint. To improve the sealing function, clamping rings may be additionally provided at the sealing element. Moreover, it has been known that the contact areas of the sealing element with the housing or the ball pivot may be provided with complementary, labyrinth-like contours.
DE 41 12 791 C1 describes, e.g., an axle strut joint with a joint housing, in which a pivotably movable ball pivot, which is formed by a ball body and two pivot projections projecting from same on diametrically opposed sides, is mounted with the interposition of at least one bearing shell. The pivot projections pass through openings of the housing. One sealing bellows each is arranged in the area of each opening of the housing between the joint housing, on the one hand, and the corresponding pivot projection, on the other hand. The housing-side edge area of each sealing bellows is held at the inner wall of the housing by means of a clamping ring, and the clamping ring is supported at a ring projection of the housing, which forms the edge of the opening of the housing and is directed inwardly. The clamping ring has an L-shaped design and is equipped with a first leg, which extends essentially in the axial direction of the housing and is springily elastic in the radial direction, and with a second leg, which extends approximately at right angles thereto, and is fastened on the side of the sealing bellows that is the outer side relative to the sealed inner wall of the housing, at its edge area having a correspondingly L-shaped profile.
This joint has the peculiarity that the ball pivot projects from the joint housing on both sides.
The drawback of such a ball-and-socket joint is, however, that besides its complicated design, it cannot assume an optimal sealing function over a long life cycle. An annular groove, into which the sealing bellows is inserted, is milled in the pivot.
The sealing bellows is in contact in this annular groove with the ball pivot under pretension, which is additionally increased by a clamping ring. However, there is a risk at this connection point of the components that contaminants may be deposited. These may be, e.g., detergents, oil residues or salt-containing solutions, which frequently occur during the operation of a vehicle during the wintertime. Thus, highly corrosive media sometimes enter this area of the ball-and-socket joint and they gradually lead to corrosion phenomena on the ball pivot, and this corrosion in turn facilitates the penetration of contaminants or moisture due to increasing porosity of the surface. The inevitable consequence is the accelerated destruction of the joint.